Self-inductance



April 9, 1935. M. OSNOS 1,996,823

SELF INDUCTANCE Filed Oct. 28, 1933 A A 1A a lllllllll WWWWWMWWW;

WWWWWWWWM WWI/WWW I l I I y l y l y l y l y l y l INVENTOR 4 Mf/VDEL 0 /V05 BY M ATTORNEY L Patented Apr. 9, 1935 Q UNITED STATES PATENT OFFICE SELF-INDUCTANCE Mendel Osnos, Berlin, Germany, assignor to Telefunken Gesellschaft fiir Drahtlose Telegraphic m. b. 11., Berlin, Germany, a corporation of Germany Application October 28, 1933, Serial No. 695,564 In Germany November 2, 1932 5 Claims. (Cl. 175-359) The present inventionrelates broadly to inincreasing but may actually decrease with inductance coils and more specifically to increase in temperature. ductance coils with variable or controllable tem- In said U. S. patent application Serial No. perature dependency. 683,240 the embodiments of self-inductances are In copending U. S. application Serial No. shown by way of example as being composed of 5 683.240 certain embodiments of self-inductances springy spirals which due to their construction are shown by way of example as springy spirals press against the surrounding cylinder. They which are arranged to press against a surroundare of practical usefulness as long as they reping cylinder preferablyof quartz. In the system resent small self-inductances. Larger self-indescribed in said application, if the cylinder is ductances however, are made of soft wire or litz 10 to be composed of quartz or the like it is very wire, thus not having an inherent springy force difficult to make the inner surface entirely cylinto cause them to be pressed against the cylinder.

drical. Hence it is difilcult to accomplish a com- A feature of the present invention comprises plete pressing of the self-induction coils against winding the self-inductances upon a cylinder the quartz cylinder; split in the longitudinal direction into two or 5 In order to avoid these drawbacks the present more portions or they are wound upon several invention proposes to arrange between the quartz cylinder parts and these only are pressed by cylinder and the self-induction coil a suitably means of a spring force or spiral spring respecsplit cylinder of a material that will easily afford tively, against the cylinder surrounding the windobtaining an accurately cylindrical inner form. ing. 20 It has been found that materials such as hard In Figure 3, numeral l is a cylinder limiting the rubber or the like give excellent results. diameter of the induction coil and which is com- In the accompanying drawing three embodiposed of quartz for instance, 2 designates the ments of the invention are shown by way of springy spiral suitably of copper, 3 is a cylinder example, of insulating material (such as pressboard, hard I Figure 1 is a partial'cross sectional view of a rubber or the like) split into two or several porform of the invention wherein the inductance tions, and 4 represents an inductionwinding coil is made of elastic material; wound upon a cylinder and consisting for in- Figure 2 shows a partial sectional view of an stance of copper strand wire. The springy spiralarrangement made up in accordance with the 2 presses the two cylinder halves and thus also invention wherein the pressing force is obtained the winding itself against the cylinder I inby an additional spring device; and, tended to limit the diameter of the winding.

Figure 3 is a partial cross sectional view of an In order to avoid losses the helix 2 will prefembodiment of the invention wherein only one erably be made of copper wire. In this case the split cylinder is utilized. helix 2 can also be used as additional self-in- In Figure la quartz cylinder lhas inserted in ductance. It is preferable to make the split it a split cylinder 3 and the inductance coil 2. between the cylinder halves or the splits be- In this particular embodiment the coil 2 is suittween the single cylinder parts as narrow as ably constructed so as to force the split cylinder possible. 40 3 up against the quartz cylinder I. In this way I claim: 40 the coil is maintained at a practically uniform 1, In an inductance 11 assembly quartz diameter. The split cylinder 3 is preferably concylinder Split l d up of insulation structed Of an i u t materialmaterial within said cylinder and a metallic Figu e 2 indi a s the pl i of the spiral coil within the split sleeve said coil being 4:, ventive idea to an unelastic induction coil. arranged so as to firmly retain the split sleeve Herein are I, 2 and 3 the same elements as those within the cylinder. in Figure 1 excepting 2 to be simply used as 2. An inductance coil comprising a quartz spring and not also as an inductance, 4 is the cylinder, a metallic spiral inductance coil enrigid-induction coil. In this case cylinder 3' is gaging the internal wall of said quartz cylinder doubly used at the inside as well as outside of and a split sleeve arrangement made of insulacoil 4. tion material within said spiral and means com- The use of the outer cylinder 3 composed of prising a metallic spiral coil engaging the inhard rubber or material highly expanding under ternal wall of the split sleeve so as to firmly reheat, give the advantage that the outer diameter tain said first named coil within said cylinder.

5 of the induction coil is not'only prevented from 3. An inductance coil comprising a quartz cylinder,

5. An inductance coil assembly comprising a cylinder made of a material having an extremely low coefiicient of expansion with changes in temperature, a split sleeve within said cylinder and a metallic spiral coil within the split sleeve said coil being arranged so as to firmly retain itself against the split sleeve while at the same time retaining the split sleeve within the cylinder.

.1 MIENDEL OSNOS. 

